Pawl-and-ratchet means



J. W. KNOPP.

PAWL AND RATCHET MEANS. APPLICATION HLED APR. 9. 1919.

Patented Jan. 27, 1920.

JULIUS W. KNOPIP, OF TOLEDO, OHIO.

IPAWL-AND-RATCHET MEANS.

Specification of Letters Patent.

Patented Jan. 27, 1920.

Application filed April 9, 1919. Serial No. 288,679.

To all whom it may concern:

Be it known that I, JULIUs WV. Know, a citizen of the United States, and a resident of Toledo, in the county of Lucas and State of Ohio, have invented a certain new and useful Pawl-and-Ratchet Means; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to a pawl and ratchet means adapted particularly for use in connection with me hanical engine cranking devices, and has for its object the provision of a simple, eflicient and improved means of this character which is quiet in its action, and which, upon a back stroke of the pawl from advanced position, locks the pawl against coaction with the ratchet until the pawl has completed such stroke when it is automatically released to permit it, upon its next forward stroke, to engage and drive the ratchet.

The invention is fully described in the following specification, and while, in its broader aspect, it is capable of embodiment in numerous forms, a preferred embodiment thereof is illustrated in the accompanying drawings, in which Figure 1 is a front elevation of the means embodying the invention in normal rest position, with the associated frame with which it coacts, in section. Fig. 2 is a fragmentary front elevation thereof, with the pawl partially advanced from rest position, and Fig. 3 is a similar view with the pawl at the forward end of its stroke and returning to normal position in released relation to the ratchet.

Referring to the drawings, 1 designates a shaft, which may comprise the crank-shaft of an engine, 2 a ratchet-wheel fixed thereto, and 3 a cranking arm, which is loosely mounted on the shaft for free turning movements relative thereto and has its outer end projecting beyond the outer edge of the ratchet-wheel and provided with a lateral segmental extension 4, which is preferably concentric to the shaft axis. A cable, chain or other draft means 5 seats in a peripheral groove in the segment 4 and extends from the opposite end of the segment to which attached, whereby a pull on the cable 5 will impart a predetermined rocking movement to the arm 3. The arm 3 when in normal position rests on the adjacent top portion of a frame or casing 6.

A pawl 7 is pivoted at 8 to the outer end portion of the arm 3 and in the present instance, extends lengthwise of the arm along the top edge thereof, and has its forward end provided with one or more teeth to adapt it to engage the teeth of the ratchetwheel 2 and impart forward rotation thereto when the arm 3 is rocked forward. The pawl 7 is provided at its rear end with a tail piece 9 between which and the arm 3 is disposed a coiled compression spring 10 acting to normally retain the pawl in engagement with the ratchet-wheel. A spur or finger 11 projects transversely from the inner side of the pawl 7 through a registering opening 12 in the arm 3 and in position for its lower or outer end to coact with the adjacent side of the frame 6 to positively retain the pawl in released position with respect to the ratchet when the arm 3 is in normal at rest position.

A catch-finger 13 projects through an opening 1 1 provided in the inner end portion of the arm 3 transverse to its rocking axis and is pivoted therein at 15. The lower end of the finger 13 is provided with a lateral extension 16, which extends lengthwise along the under side of the arm 3 and receives the outer end thrust of a coiled compression spring 17 that is mounted in a socket in the under side of the arm 3. The extension 16 extends over the frame 6 in position to coact therewith and to be held thereby in close parallel relation to the arm 3 when said arm is in normal at rest position, as shown in Fig. 1. Then the pawl 7 is in engagement with the ratchet-wheel teeth the free end of the catch-finger 13 bears rearwardly against a lug or lateral extension 18 on the nose or forward end portion of the pawl, and, upon a movement of the pawl to released position relative to the ratchet teeth, the catch finger 13, under the action of the spring 17, is swung into outward holding engagement with the lug 18 to retain the pawl free from engagement with the ratchet teeth. When the arm 13 is in normal at rest position, however, the spur 11 coacts with the frame 6 to retain the pawl out of engagement with the ratchet teeth. and the catch-finger extension 16 is held by said frame in compressed position with its catchfinger released from the pawl.

It is evident in the use of my device that when the cranking arm 3 is in the normal at rest or inoperative position shown in Fig. 1, the pawl 7 is held out of engagement with the ratchet teeth by engagement of the spur 11 with the frame 6, and the catch-finger 13 is held out of pawl engaging position by engag ment of its extension 16 with said frame. WVhen a cranking or forward movement is imparted to the arm 3 from its normal position, the pawl 7 immediately drops into engagement with the ratchet teeth to impart rotation to the ratchet, and the catch finger is permitted to move, under the action of its spring 17, into stop engagement with the forward end of the pawl, as illustrated in Fig. 2. \Vhen the strok is completed and the arm 3 commences its return stroke, the pawl rides outwardly over the ends of the ratchet teeth a suflicient distance to permit the catch-finger 13 to move into the SIIPPUlting holding engagement therewith shown in Fig. 3, in which position the pawl is held so that it just frees the teeth as it passes thereover on the return stroke, thus preventing the objectionable clicking occasioned by the pawl riding over the ratchet teeth in engage ment therewith. When the arm 3 is near the completion of its return stroke, the extension 16 on the catch-finger engages the frame (3 and effects a rocking of the catch-linger to release the pawl and at approximately the same time, or when the arm has completed the stroke, the spur 11 on the pawl engages the frame and retains the pawl disengaged from the ratchet.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims,

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is,

1. In combination, a ratchet-wheel, a member mounted for swinging movements concentric thereto, a pawl member carried by said member for normal engagement with said wheel, a catch carried by one of said members and normally movable to engage the other to retain the pawl out of engagement with said wheel, and means acting on the pawl when in one position of its movement to hold it released from the ratchet wheel and at the same time acting on the catch to hold it out of pawl engaging position.

2. In combination, a ratchet-wheel, an arm mounted for swinging movements concentric thereto, a pawl carried by said arm for normal engagement with said wheel, a catch member carried by said arm and adapted to normally engage said pawl to retain it out of engagement with said wheel, and means acting on the pawl when the arm is in one position of its movement to hold the pawl released from the ratchet-wheel and at the same time acting on said catch member to hold it released from the pawl.

3. In combination, a ratchet-wheel, an arm mounted for swinging movements concentric thereto, a pawl carried by said arm. for normal engagement with said wheel, means operable to automatically engage and retain the pawl out of engagement with the ratchet wheel during a return of the pawl from a ratchet-wheel advancing movement and means operable to hold said pawl out of engagement with the ratchet-wheel and to release said first means from the pawl when said arm is in one position of its movement.

4:. In combination, a ratchet-wheel, an arm mounted for swinging movements concentric thereto, a pawl carried by said arm for engagement with said wheel, said pawl having a spur projecting laterally therefrom, a catch member carried by said arm for engagement with the pawl to retain it out of engagement with the ratchet-wheel during a back stroke of the pawl, said catchfinger having an extension, means acting on the catch-finger to urge its engagement with the pawl, and frame for acting on said spur to retain the pawl disengaged from the ratchet-wheel and for acting on said extension to retain the cat h-finger out of engagement with the pawl when the arm is in normal at rest position at the rear end of its stroke.

In testimony whereof, I have hereunto signed my name to this specification.

JULIUS W. KNOPP. 

